Mode of and apparatus for reducing grain and simultaneously purifying the products



2 Sheets-Sheet 1 G. MILBANK. Modes of and Apparatus for Reducing Grainand Simultaneously Purifying the Products thereof. No. 229,445. PatentedJune 29, 1880.

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N PETERS, PHOTO-L|THOGRAPNER. WASHINGTON. D C.

2 Sheets-Sheet 2. G. MILBANK. Modes of and Apparatus for Reducing Grainand Simultaneously Purifying the Products thereof.

No. 229,445. Patented June 29,1880.

1* F I Z 8 a y E A 2, 6 a? a o I I a s 1 d d mm BB 6L t I B j i! a I e aATTEST; INVENTORZ g0 .%2'J5 4 jj i zfiwzez a N4 PETERS.PHOTO-UTHDGRAPMER, WASHINGTON. D C.

UNITED STATES PATENT OFFICE.

GEORGE MILBANK, OF OHILLIGOTHE, MISSOURI.

MODE OF AND APPARATUS FOR REDUCING GRAIN AND SIMULTANEOUSLY PURIFYINGTHE PRODUCTS THEREOF.

SPECIFICATION forming part of Letters Patent No. 229,445, dated June 29,1880.

Application filed November 26, 1879.

To all whom it may concern:

Be it known that I, GEORGE MILBANK, of

Ohillicothe, Livingston county, and State of Missouri, have invented anImproved Apparatus to Reduce and Purify Grain, &c., of which thefollowing is a specification.

My improvements are designed to achieve a more perfect reduction andpurification of larger substances or particles when the same aresubjected to a crushing, purifying,.or grinding action.

Specially to reduce and purify grain, middlings, meal, &c., when thefeed is passed between a pair of millstones, my improvements aredesigned to produce such a reduction that each or all particlescomposing the product shall approximate as near as possible to the sameor the desired size-in other words, producing a more even reduction oflarger substances to smaller and the better purification of same.

When grain is subjected to the action of stones or grinding bodies, ascustomary, it can be stated that the following forces are called intoaction--viz., centrifugal force, gravitation dress of the stones,air-currents, or all forces tending to pass the feed in the samedirection viz., from center to periphery of the stones. Morespecifically stated, each of said forces acts as follows The centrifugalforce has a greater eft'eet,or will throw farther and with more forcethe larger substances or grains in proportion to their size or specificgravity. Gravitation, also, under ordinary circumstances, has a greatereffect on the larger or heavier bodies, causing them to move downwardfaster and with more force in proportion to their size and specificgravity. The dress of the stones also tends to move the larger bodiesfaster than the smaller, the latter naturally lying low and lodging inthe hollow of the furrows. Aircurrents, however, act with or have agreater effect on the smaller and lighter particles than upon theheavier, in proportion to their size and gravity.

Since, therefore, the ordinary method of arranging the parts is suchthat each and all of these named forces act in the same direction;further, since these forces act dilferently upon the larger and smallerparticles, and, lastly,

since by reduction the substances and particles change their size,weight, and specific gravity, the result or product obtained isnecessarily unequaled in this: that some of the particles are ground toofine, others too coarse, and the product lacks uniformity in the size ofits particles.

According to my improvements the abovenamed forces are all utilized, butplaced under the control of the operator, and, as will hereinafterappear, enabling him to regulate the passage and time ofpassage of eachand all particles from the eye to the skirt, or in vice versa direction,and at same time subject each and all of the particles to the desiredreduction, or like reduction and result as to size.

My improvements in purifying reduced particles consist in separating thelighter pulverulent matter, or matter of less specific gravity, from thepurer or more dense matter before said atoms or particles come incontact with each other after being reduced, and before they find alodgment or resting-place or are massed or bulked.

Ordinarily the reduced product is permitted to have its particles tocome in contact with each other or become bulked, and in so doing theimpure or pulverulent matter is more or less rubbed in or on to thepurer matter, and hence it is rendered the more difficult or impossibleto properly purify.

Of the drawings, Sheet I, Figure l is a part sectional and end elevationof my improved apparatus adapted tolreduce and purify grain, 850., whenthe same is passed or fed from eye to skirt of stones, as indicated bythe arrows. Sheet II, Fig. 2 is a sectional elevation of the sameapparatus, showing it adapted to reduce and purify grain, &c., whenpassed from the periphery to the center of the stones, as indicated bythe arrows.

A A represent the pair of millstones, the former being the bed andsecured stationary, the latter being the runner. This relationship ofthe stones can be reversed, so that the top shall be stationary, thelower one the moving stone; or both stones can be revolved,,each inopposite direction to the other, or revolved both in the same directionbut at different speed. Otherwise the stones can be set and operated Oin manner usual. The dress of the stones is also, as usual, to suit thedirection of the revolving stone, or to feed the grain from the eye tothe skirt, or vice versa.

Forming part of the bed-stone A is a receptacle, preferably acone-shaped chamber, B. This chamber receives the reduced product incase the feed is from periphery to center, the discharge taking placethrough the valve h, and said valve is closed when the feed is in theopposite direction tothatjust stated. Also through said chamber B theair-currents pass during the operation of reduction and the pro cess ofpurifying the product.

b is an air-inlet valve, and is to regulate the admission of air intosaid chamber B, said valve being closed when the feed is from center toperiphery.

The runner A is supported, as usual, by an adjustable step consisting ofthe spindle (1, arranged to pass through the bed-stone and its chamberB, the spindle foot stalk having its toe resting in a footbridge, a,secured to the bridge-tree a, controlled by the lighter screw a all asshown. The runner A can therefore be raised or lowered, so as to placethe faces of the stones farther apart or closer together, as required.

A is the pulley connecting to power source to revolve the runner.Arranged in the center of the runner A, and secured to the spindle a,are cone-shaped deflectors C. These deflectors consist of an inside conerim or face, 0, with one or more duplicates, c, on the outside, leavingclearances or passages between, as shown. The special purposes for whichthese deflectors C are intended is to cause the air-currents in thechamber B to pass up or through or between the cone-faces c c, and thusbecome more divided and more equalized.

D is the outside cylinder-casing, and is supported stationary tosurround the pair of millstones. The casing I) has its closed top formedwith a short cylindrical neck, (I, while the bottom of said casing isleft open. Near the bottom edge of the casing, and entirely surroundingsame, are apertures d, for the entrance of air from the outside.

D is a bottom rim, consisting simply of a horizontal rim joined at rightangles to a vertical rim, and said bottom rim is titted movably to thebottom edge of casing I). By moving the bottom rim, 1), more or lessover the inlet-apertures d the passage of air-currents can be regulatedor controlled.

E is the central or main spout, its lower end partly extending below thecylinder-neck of the top stone, as shown. At 0 this spout E has a teedpening, and this is controlled by a slide or valve, 6, as shown. In casethe feed is to pass to the center or eye of the stones it is fed throughthis opening 0, the feed so passing being easily regulated by the valve0. In case the feed is to pass to the periphery of the stones thefeed'spout or hopper F is used, and, as shown, it is movably arrangedbetween the neck d of the casing and the central spout,

with feed-passage f for the downward passage of the grain. When,therefore, the feedhopper F is raised (see Fig. 2) to clear the back ofthe top stone the feed or grain can pass down f over the back of thestone to the periphery, and said fecd-hopper is moved down to close thepassage-way f in case the feeding of the grain is to the center, asshown in Fig. l.

G is the blast-fan spout, communicating to the skirt of the stones bybeing connected to the top of the cylinder-casing D. G is the blast-fancasing. G2 is the blast-fan inside said casing. g is the blast-fanspout, having its one end in communication with the spout G, its otherend with the central spout, E. g is the branch suction-fan spout, havingits upper end communicating with E and its lower end to G.

The central spout, E, connects at top to the suction-fan chamber H,which contains suction-fan 11. Both blast-fan and suction-fans areconnected to the shaft H and revolved by power-source applied to thepulley-wheel H.

h h h h represent the respective slides in each of the spouts justenumerated. By means of these slides the operator can regulate andcontrol the blast and suction or upward and downward acting air-currentsto suit the operation in either casethat is, passing the. grain orsubstances from the periphery to the eye, or vice versa.

I is apressure-valve, similar in construction and operation to anordinarysteam safetyvalve. By means of this pressure-valve the operatorcan regulate the pressure of the air force in the casing I) to suit thereduction of the grain, and specially to cause said air force todetermine the size to which the particles I shall be reduced. Also, saidvalve can beset to form the required inlet or outlet for air to and fromthe casing I).

I is also a pressure-valve, to regulate andsuit the suction force todetermine the size to which the particles shall be reduced, andotherwise can be used as an inlet and outlet for air. 3

l is a scraper secured to the revolving stone,

and only used, in case the feed is passed from the eye to the skirt, forpurposes of moving the reduced product, which falls out at theperipihery into the bottom I), to be discharged at the outlet 1'. a" isa flap-valve to open or shut the outlet 1'.

All the parts thus constructed and arranged, the complete operation ofreducing the grain or substances in both cases-that is, passing the feedfrom the periphery to the eye of the stones, or from theeye toperiphery-will now be described.

By referring to Fig. 2 the position of the various parts is shown whenthe operation is to reduce the feed fed to and passing from theperiphery to the center. I

More particularly stated, the hopper Fisset. to open the passage f topermit the feed to pass over the back of the stone to the periphery, the

bottom rim, D, is set to form a closed bottom for the casing D, andhence a receptacle for the feed to collect and fill until alevel isreached that further passes the feed between the faces of the stones,the discharge-valve at i is closed, the scraper I is removed, and, sofar as progucing an air-current, this can be done, first,

BZast.-Hence, open slide h, close h k W, and the blast can then bedirected down G to fill the chamber of D, and pass between the faces ofthe stones into the chamber B, and out with the reduced product at 12.Here beit noted that I have an air-current entering at the pe ripheryand out at the eye, in opposition to centrifugal force.

Suctiom-Jn place of the blast just stated, suction can be used. Thus,open slide h, also pressure-valve I, for air to enter D; close allremaining valves, and suction or air-currents will pass in at I over thestone, in at the periphery, between the faces of the stones, to thecenter. Here, again, the suction or air-current .is in oppositedirection to centrifugal force.

Suction and blast combined.l can use suction and blast combined. Thus,open slides h h, close k h and all remaining openings. The blast willthen pass down. G and suction up E, producing together an air current orcurrents, acting in the same direction as blast and suction alone, andin opposite direction to centrifugal force.

Opposed to gravitation.-Also, the blast or suction, each singly orcombined, can be made to produce air-currents in opposition togravitation. For this purpose the same means just described are used.The faces of the stones, however, are made such as to have their inclinelowest at the periphery and highest point near the center.

Opposed to dress.-Also, by the same means, in case the dress is made topass the material from the center to circumference, the air currents orforce can operate in reverse direction to the dress. Also, by the samemeans-that is, passing the air-currents from periphery to the eye-I cancause the furrows or dress, or gravitation, either singly or bothcombined, to assistthe said currents or force so directed. Thus, in thecase of the dress, this is done by sim ply changing said dress to suitthe direction or, as another way, by revolving the stone in oppositedirection. In case of gravity this action is achieved by suiting theinclination of the faces of the stones to be in the same direction asthe said acting air-current.

By referring to Fig. l, the position of the various parts is shown whenthe operation is to reduce the feed fed from the eye to the skirt. Thehopper F closes the passage-way f below. The slide 6 is properly openedto permit the feed to pass down the center and fill the chamber B untila level is reached, permitting the feed to pass between the faces of thestones and outward from same. The bottom of B is therefore closed.

Blast from center to periphery-This can be done by closing slides k h,opening h. In case the inclination of the faces of the stones is such asto have gravity to be directed inward, then the said blast orair-current through 9 is in opposite direction to gravity. In case thedress is laid to move the material inward, the said air-current soderived through 9 down the center directed to the periphery will or canbe in opposite direction to said dress. Likewise the suction can bedirected to pass from center to periphery. Hence, close slides h it,open h and pressure-valve I; close apertures d below. The suction-inletwill then be at I down or through the center, between the faces of thestones, to their periphery, and upward through g into suction-fan.

In case the dress or furrows or the inclination of the faces of thestones is made the same as just stated in using the blast--that is, saiddress and gravitation directed inwardthen the suction so acting through9' will be in opposition to said dress and gravitation; or blast andsuction can, combinedly, act from center to periphery. Thus, close h itopen h h The blast will then pass down the eye out at the periphery atsame time with suction up and out at g.

I am thus enabled, when the feed is passed from the periphery to the eyeand out at the center, to cause an air current or force to act inreverse direction to centrifugal force, or to gravitation, or to thedress of the stones; or I can cause the said air-current to assist (orbe assisted by) the dress, gravitation, or both said forces combined. Ina similar manner, in case the feed is passed from the eye to and out atthe periphery, I can cause an air current or force to act in the samedirection as centrifugal force, but in reverse direction to gravity orto the dress; or said air-current can assist (or be assisted by) thedress of the stones, or gravity, or both said forces combined.

In so causing one or more forces to operate in one direction while oneor more forces operate in another direction, I achieve the followingimportant results and desirable advantages: The larger particles can beretained longer between the faces of the stones, and by that meansreduce said particles more, while the smaller particles can be passedquicker or sooner from out between the faces, and by that means stop thefurther reduction of said smaller particles.

The centrifugal force, as previously stated, naturally having thegreatest eifect on the larger particles, these would be thrown outwardor toward the periphery; but the aircurrent when passed in the peripheryand out at center, in its nature having the greatest effect upon thesmaller particles, the latter are forced out at the center immediately,and hence separated from the larger particles and saved from furtherreduction.

In cases Where the upper body is revolving and its face is set suitablydistant from the face of the lower stone, by passing an air-current inopposite direction to centrifugal force the IIO latter force loses allpower over the particles when the same becomes smaller than the spacebetween the faces of the two bodies, and the air-current, having noopposing force, (the upper face not reaching the small particles,) requires therefore no more power than sufficient to sweep or pass theparticles of! from the lower face or surface.

In all cases the required power of air current or currents or airpressure or force can be obtained by opening or closing the slides or byloading with or relieving from weight the pressurevalves.

If necessary to assist the air-current to pass the grain or othersubstances in at the periphery, the dress is laid in such a direction aswill carry the material toward the center. The dress acting with thegreatest effect upon the largest particles (the same as centrifugalforce) assists the air-currents to pass the larger particles inward tothe center and counteract the tendency of centrifugal force to throw thelarger particles outward.

To assist or oppose centrifugal force or aircurrent or dress by gravity,the faces of the stones will be made to incline inward toward the centeror outward from the center, as may be necessary. if, however, I pass anair-current from the center to periphery, the air-current will beassisted by centrifugal force, and it can be in opposite direction tothe movement of the material by the dress or by gravity, or be in thesame direction as the movement of the material by the dress and gravity,according to the way the dress is laid or the faces are made to incline,and as previously stated.

Specially it will be noted that by arranging the air-current to move inone direction (and having the greatest control upon the smallestparticles) and centrifugal force or the dress or gravity operating inreverse direction, said forces having the greatest effect or control onthe largest particles, the reduction going on in the meanwhile, thatwhile the said forces acting on the larger particles or losing controlby said particles becoming smaller, the aircnrrent is gaining controlover the particles to the same extent that the said other named forcesare losing; and hence, when the equilibrium is passed, the aircurrentsare the coiltrolhng force to give freedom to the particles that havebeen reduced to the desired size by passing the same out from betweenthe faces.

During the operation ot'so reducing the grain or other substances thepurification of the reduced product according to my invention is asfollows: When the reduced product is to be received in the chamber B, myimprovement consists in separating and purifying the said product beforeit lodges or is bulked or massed in the said chamber. This result Iachieve by using suction'force through chamber B, its valve 1) beingsuitably opened, the said force then passing upward from the centertosuctionfan. The air-currents so produced by the sucupon the reducedparticles immediately or as soon as the same are freed from the stones,causing the lighter stuff and impurities to be separated from theheavier and purer, the former to be forced upward with the suction, thelatter to fall into the bottom of chamber B. Be it noted the action ofsuction to separate and purify the particles takes place before thesetouch each other and before they find a resting-place, and consequentlyinsures a better and more perfect purification of the product. Theair-currents passing between the faces of the stones assist the suctionand air currents ascending upward, and by this means still furtherenhance the process of purification. The deflectors C also enhance theprocess of separating the pure and impure particles by establishing amore uniform action on the part of the air-currents throughout theinterior of the chamber B. Also, blast and suction can both be used tocarry out this process of purification.

\Vhat I claim is- 1. The described method of reducing grain or othersubstances, consisting, essentially, in subjecting the material undertreatment to the action of reducing-disks and an air-currentsimultaneously, the said air-current passing between the disks andconveying the reduced material in opposition to the centrifugal actionof the same.

2. The described method of reducing grain or other substances,consisting, essentially, in subjecting the material under treatment tothe action of reducing-disks and an air-current simultaneously, the saidcurrent passing between thedisks and con veyiug the reduced material inopposition to the action of the dress of the same.

3. The described method of reducing grain or other substances,consisting,essentially, in subjecting the material under treatment tothe action of reducing-surfaces set in a plane other than the horizontaland an air-current simultaneousl y, the said air-current passing betweenthe reducing-surfaces and conveying the reduced material in oppositionto the action of gravitation.

4. The described method of reducing grain or other substances,consisting, essentially, in subjecting the material under treatment tothe action of reducing-disks and an air-current simultaneously, thedress of the reducing-disks and the air-current combined conveying thereduced material in opposition to the centrifugal action.

5. The described method of reducing grain or other substances,consisting. essentially, in subjecting the material under treatment tothe action of reducing-disks having reducing-surfaces inclined from thehorizontal and an aircurrent simultaneously, the dress of the inclineddisks and the air-current combined conveyin g the reduced material inopposition to the action of gravitation.

(i. In combination with the reducing-disks tiou, acting in the saiddirection, catch or act I A A, the casing D and fan mechanism, sub- IIOstantially as described, connected therewith, the construction beingsuch that an air-current is delivered by the fan mechanism to theperiphery of the disks and through between the same to the eye.

7. In combination with the reducing-disks A A, an interiorchamber andfan mechanism, substantially as described, connected with the chamber,the construction being such that an air-current may be drawn throughbetween the disks from the periphery to the eye, as described.

8. The combination, with reducing disks having the periphery of thegrinding-surfaces higher than the eye, of mechanism, substantially asdescribed, for producing an air-current, the construction being suchthat the action of the air-current is opposed to the action ofgravitation.

9. The combination, with reducing-disks having the periphery of thegrindingsurfaces lower than the eye, of mechanism, substantially asdescribed, for producing an air-current, the construction being suchthat the aircurrent is opposed to the action of gravitation.

10. The receiving-chamber B, located within the reducing-disks and inopen unbroken communication with the eye of the same, in combinationwith mechanism for reducing the grain or other substances, and mechanismfor furnishing an air-current, and thereby delivering it to thereceiving-chamber in opposition to the centrifugal action of thereducing-disks.

11. In combination with the reducing-disks delivering material at theeye and mechanism, substantially as described, for producing an upwardair-current, the deflector G, for breaking up or dividing theair-current.

12. The described method of reducing and purifying grain and othersubstances, consistin g, essentially, in passing the material betweenthe reducingdisks, with an air-current opposed to the centrifugalaction, and in carrying upward from the eye the lighter particles by anascending air-current, by means of which action the heavy and lightparticles are separated before being bulked.

13. In combination with the millstones A A, having their faces dressedand made to incline so as to be lowest at the periphery and highest nearthe center, the casin g D, the feedhopper F, the bottom rim, D, thechamber B, closed at bottom, the spouts G and E, having slides, thesuction and blast-tan connections, by means whereof the blast singly, orsuction singly, or both suction and blast combined, can be passed fromthe periphery to the eye of the bodies that produce reduction.

14. In combination with the bodies A A, having their faces dressed topass the material from the center to circumference, the casing D,feed-hopper F, the bottom D, the chamber B, the spouts G E, havingslides, suction and blast-fan connections, by means whereof the blastsingly, or suction singly, or both blast and suction combined, can bepassed from the periphery to the eye in opposition to the dress of thesaid bodies, producing reduction, in the manner and for the purposes setforth.

In testimony of said invention I have hereunto set my hand.

GEORGE MI'LBANK.

Witnesses:

WILLIAM W. HERTHEL, JOHN M. HERTJIEL.

